1. Field of the Invention
This invention relates to wind propelled vehicles such as sailboats, sailboards, iceboats and land vehicles having a sail supported by a mast and particularly to wide base or hull vehicles wherein the position of the sail is directly controllable by the user of such vehicle through movement of an arcuate boom on such mast.
2. Description of the Prior Art
In addition, to the traditional use of sail propulsion in large as well as small sail boats, sail propulsion has also been used in many other forms including for example, iceboats and surfboards and for land craft such as skateboards and sleds as well as other lightweight small craft. Typically, a sail is provided on a mast that is rigidly secured to the craft in a vertical position, or else the sail and mast are entwined in a network of riggings and control mechanisms.
More recently, wind propulsion vehicles of the type described in U.S. Pat. No. 3,487,800 issued to H. Schweitzer have gained popularity. The Schweitzer type vehicles add a certain dimension of wind responsiveness and speed to small sail craft and changes the vehicles normal ride and control characteristics by providing a vehicle body, such as a surfboard, and a mast which is universally mounted so as to be moveable in any direction (i.e. it has three degrees of freedom). The mast supports a pair of arcuately connected curved boom and a sail between said booms. The position of the mast is controllable by the user and is free from pivotal restraint in the absence of such control.
While wind propelled vehicles of the type described by Schweitzer have gained popularity, they are often very difficult to control, especially with larger sails which are generally more desirable for obtaining greater speeds or in high wind conditions. This is especially true when the user lacks the strength to maintain control of the position of the sail in such conditions, leading the vehicle to capsize.
A need therefore exists to improve the ease of controlling the vehicle, especially with larger sails and/or in high wind conditions.